NEW DIRECTIONS IN ATOMIC SPECTROMETRIC ANALYSIS

原子光谱分析方法是最常用的 测定样品元素组成的技术 生物医学，生物化学，制药科学，法医学研究， 在其他领域。不幸的是，现有的原子分析方法 在一些重要的领域， 个方面这些缺点中最突出的是敏感性不足， 速度和元素覆盖率此外，对于许多应用程序， 样本量过大，精度不足，准确度 取决于样品的总体组成或样品的能力， 分析员将样品和标准品紧密匹配。在这一计划中， 的调查概述，以继续研究，开始在美国国立卫生研究院 赞助。在这些研究中，一种新的原子光谱法， 仪器的设计、构造和测试都是在真实的样品上进行的。 首先提出了论证，表明原子的最佳来源， 光谱法是一种串联光谱法，由两种光谱法组装而成， 独立的设备。第一源被分配接受 待分析物质的样品，并将其分解为 尽可能多地分解成其组成原子。这些原子是 然后直接进入第二个来源，选择它的能力， 用于随后的质谱分析。因为每个 两个源被赋予一个特定的任务，它可以选择它的能力 执行该任务;此外，其操作条件可以是 为这个目的而优化。结果是更高的灵敏度， 背景和样品相关的误差，以及更好的精度。时间- 飞行质谱仪（TOFMS），原子离子将被送入其中 也很不寻常与用于原子分析的传统质谱仪不同， 分析，飞行时间质谱仪可以产生一个完整的原子质谱， 时间短至50微秒，因此非常适合分析瞬态或 微小的样本。此外，由于TOFMS测量的所有离子都是 在单个时刻从串联源提取的离子， 粒子数表示源中离子的“快照”。 因此，离子信号可以被比率化或标准化以改善 更精确。最后，预计新系统将特别 当与激光烧蚀一起用于微取样时，甚至 单次激光发射将产生高灵敏度的元素 分析或同位素比率，使空间分辨率能够实现， 待分析的生物样品和微升体积的样品溶液 迅速

Atomic spectrometric methods of analysis are the most commonly used techniques for determining the elemental composition of samples in biomedicine, biochemistry, pharmaceutical science, forensic studies, and in other fields. Unfortunately, existing methods of atomic analysis fall short of meeting the modern needs of these fields in a number of important respects. Prominent among these shortcomings are inadequate sensitivity, speed, and elemental coverage. Also, for many applications the required sample size is excessive, precision is inadequate, and accuracy is dependent on the overall composition of a sample or on the ability of an analyst to match samples and standards closely. In this proposal, a plan of investigation is outlined to continue studies that were begun under NIH sponsorship. In these investigations, a new kind of atomic spectrometric instrument is to be designed, constructed, and tested on real samples. Arguments are first put forward to show that the best source for atomic spectrometry is a tandem one that is assembled from two otherwise independent devices. A first source is assigned the function of accepting a sample of the substance to be analyzed and decomposing it as quantitatively as possible into its constituent atoms. These atoms are then directed into a second source, chosen for its ability to ionize these atoms for subsequent analysis by mass spectrometry. Because each of the two sources is given a specific task, it can be selected for its ability to perform that task; furthermore, its operating conditions can be optimized for that purpose. The result is higher sensitivity, reduced background and sample-dependent errors, and better precision. The time-of- flight mass spectrometer (TOFMS) into which the atomic ions are to be sent is also unusual. Unlike conventional mass spectrometers used for atomic analysis, the TOFMS can produce a complete atomic mass spectrum in as little as 50 microseconds, so it is well suited for analyzing transient or tiny samples. Also, because all the ions measured by the TOFMS are extracted from the tandem source at a single instant in time, that ion population represents a "snapshot" of the ions in the source. Consequently, ion signals can be ratioed or normalized to improve precision further. Lastly, the new system is expected to be especially powerful when employed with laser ablation for microsampling. Even a single laser shot is projected to yield high-sensitivity elemental analyses or isotope ratios, enabling spatial resolution to be achieved in biological samples and microliter-volume sample solutions to be analyzed rapidly.